ΔE 20.6, loose: different enough that you should pick on purpose. Dark Sand is noticeably lighter, cooler than Petroleum Brown.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Dark Sand is noticeably lighter, cooler than Petroleum Brown.
The same difference applies the other way round: Petroleum Brown is noticeably darker, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Petroleum Brown on the colour wheel See Dark Sand on the colour wheel
All matches: Petroleum Brown equivalents · Dark Sand equivalents